The toxicokinetic behavior of chlorobenzenes in earthworms (Eisenia andrei): experiments in water.

The toxicokinetic behavior of five chlorobenzenes in earthworms (Eisenia andrei) was studied. Because exposure in soil is difficult to control, worms were kept in water. Bioconcentration factors (BCF) were studied in a static test system. The results show that a steady-state concentration in worms is reached within 5 days. BCF values increased with increasing octanol-water partition coefficient (Kow). To determine elimination rate constants (k2), worms were exposed to a mixture of chlorobenzenes for 6 days followed by a depuration period of 21 days. The data of the elimination process are described by one-compartment first order kinetics. Hexachlorobenzene was not eliminated within the observed period. Bioconcentration factors increase and elimination rate constants (k2 values) decrease with increasing log Kow. The resulting BCF and k2 values are comparable with those found in fish studies.